Household appliances (e.g. dishwashers, clothes washers, etc.) have a need for disinfectants, bleaching solutions, whiteners, deodorizers, or in other words, a cleansing agent. Common surfaces often require cleansing or sanitizing. It would be an advancement to provide an apparatus for generating and dispensing cleansing, sanitizing, and antimicrobial agents as needed for appliances or surfaces that may require such agents.
In some methods, sodium hypochlorite is prepared by absorbing chlorine gas into cold sodium hydroxide solution to induce the following reaction:2NaOH+Cl2⇄NaCl+NaOCl+H2O
The sodium hydroxide and chlorine reagents input into this process may be commercially produced by the chloralkali process. For use in this reaction, there is generally no need to isolate the reagents, thus, NaOCl may be prepared in an industrial setting by electrolyzing sodium chloride solution without any separation or barrier between the anode and the cathode. In this process, the reaction solution is generally maintained at a temperature below about 40° C. in order to prevent the formation of sodium chlorate. As a result, commercially-prepared sodium hypochlorite solutions generally contain amounts of sodium chloride as a primary byproduct.
Hypochlorous acid (also known as chloric(I) acid) is a weak acid with the chemical formula HClO. HClO is used as a bleach, an oxidizer, a deodorant, and a disinfectant. HClO has been approved by the U.S. FDA for use on food in washing and cleaning applications. HClO has also been approved for use on human skin as a cleansing and sanitizing agent. It is also reported to promote wound healing. Addition of chlorine to water gives both hypochlorous acid and hydrochloric acid (HCl):Cl2+H2→HOCl+HCl
Hypochlorous acid cannot be isolated in pure form due to rapid equilibration with the anion hypochlorite (OCl−) and hydrogen ion (H+):

It would be an advancement in the art to provide an apparatus and method to generate sodium hypochlorite (NaOCl) or hypochlorous acid (HOCl) on demand. Other known methods require the storage and transport of sodium hydroxide and of chlorine gas which is a highly toxic substance. The present invention overcomes this problem using electrochemical processes for the production of sodium hypochlorite or hypochlorous acid. More particularly, the present invention provides an electrochemical process for producing sodium hypochlorite or hypochlorous acid using readily available and safe starting materials.